This date is shared between the idle timer and hanshake timeout. So, it should be
useful to dump the expiration date of the idle timer task itself, in place of the
idle timer expiration date. This way, the handshake timeout value will be visible
during the handshake from CLI "show quic full" command.
Due to the fact that several variable values (rtt_var, srtt) were stored as multiple
of their real values, some calculations were less accurate as expected.
Stop storing 4*rtt_var values, and 8*srtt values.
Adjust all the impacted statements.
Must be backported as far as 2.6.
